Just noticed this explanation here http://www.dogpile.com/info.dogpl/search/help/about.htm Looks like these people are true professionals, that's a quite scientific explanation, don't you think?
Not really It is an idea that many have had before them and I expect many will have in the future. Anyhow the business model of Dogpile is seriously flawed because they blend organic search results with sites appearing as PPC ads on the main search engines. Users are obviously not attracted by this, which is why they appear very infrequently in all the server logs I have ever looked at in detail. - Michael
Yeah, I thought a lot about this question too... I het some uniques from it also, actually that's the only way I know it's still alive, when I see some referers from it